Concrete-mixer.



PATENTED OCT. 10, 1905.

H. MISGAMPBELL. CONCRETE MIXER.

APPLICATION FILED OCT. 23, 1902.

3 SHEETS-SHEET 1..

I \lllll No. 801,329. PATENTED OCT. 10, 1906. H MISCAMPBELL CONCRETEMIXER.

APPLICATION FILED 0M 23 1902 3 SHEETS-SHEET 2.

. gg MN No. 801,329. PATENTED OGT.10, 1905. H. MI'SCAMPBELL.

CONCRETE MIXER.

APPLICATION FILED 0GT.23.1902

3 SHEETS-SHEET 3.

UNITED STATES HUGH MISOAMPBELL, DULUTH, MINNESOTA.

CONCRETE-MIXER.

No. 8o1,329.

Specification of Letters Patent.

Patented Oct. 10, 1905.

Application filed October 28, 1902. Serial H0 128,457.

T 0 (tZZ whom, it may concern/.-

Be it known that I, HUGH MIsoAMPBnLL, a citizen of the UnitedStates,residing at Duluth, in the county of St. Louis and State ofMinnesota, have invented certain new and usefulImprovements inConcrete-Mixers; and I do hereby declare the following to beafull,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

This invention relates to improvements in apparatus for mixing concreteand similar substances.

It consists in an annular receptacle with a revoluble floor mounted on asuitable base, a stationary frame positioned over such receptacle, fromwhich frame depend stirring-plows attached to beams secured to the framein such manner as to permit of their oscillation within assigned bounds.

It consists, further, in the interposition of cushion-blocks between thebeams, to which the plows are attached, and the surfaces limiting theoscillation of said beams.

It consists also in the positioning of trapdoors in the revoluble floorof the aforementioned annular receptacle, together with improved andconvenient means of operating such doors, so as to permit the readydischarge of the concrete or other mixture therefrom.

It further consists in certain other novel constructions, combinations,and arrangements of parts, as will be hereinafter more fully describedand claimed.

In the accompanying drawings, Figure 1 is a top plan view of aconcrete-mixer embodying the present invention. Fig. 2 is a verticalcentral section through the same. Fig. 3 is an inverted plan view of thefloor of the said mixer. Fig. I is an enlarged detail view of a portionof the plow-frame, showing the manner of securing the individual plowsthereto. Fig. 5 is a detail view of one of the tripping mechanisms forengaging the trap-dooroperating devices. Fig. 6 is a detailed view ofthe mechanism for operating the scraper. Fig. 7 is a detail view of thetrap-door-latching device. Fig. 8 is a detail view of thetrap-door-closing device. Fig. 9 is a detail view of one of the latchesfor the swinging doors. Fig. 10 is a detail perspective view showing theshaft and arms for operating one of the doors. Fig. 11 is a detailperspective view of one of the anchoring-plates of the floor-bracers.

In mixing concrete or other similar substances it is desirable to havethe mechanism for accomplishing the result so constructed that thecondition of the materials being operated upon may be apparent to theeye of the operator at all times. I find by the use of my improvedmixing apparatus that I am enabled to mix large quantities of concreteat one time in an even and thorough mannerand yet have the whole masswithin the vision of the party superintending the operation, so that hecan see whether the material is too wet or toodry, for instance, orwhether it is needful to add a little more of one material or ofanother. In developing the invention along practical lines I employ anopen'floor or platform, as 1, which is supported uponasuitable framework2, preferably formed of beams or girders ex tending radially beneath thesame. The frame 2 is provided upon its under side with an annular trackor grooved plate, as 3, which faces an upwardly projectingsimilarlygrooved annular plate 4, arranged upon the foundation 5 of themachine. Balls forming ball-bearings, as at 6, are interposed betweenthe grooved plates to form a supporting ballbearing for the frame 2 andthe floor 1. The said floor and the frame carrying the same are thusmounted so that they may be revolved upon said ball-bearing above thefoundation 5 of the machine. A vertical central standard or post 7 ismounted upon the foundation 5 and extends upwardly through the center ofthe floor-frame 2, passing through suitable bearings, as 8 and 9,secured to the said floorframe. The bearing9 is formed inastrengthening-plate 10, which is located upon the upper surfaces of thebeams composing the frame 2. In order to strengthen the said frame, Ipreferably arrange bracing-yokes 11 11 so as to inclose a portion of thesaid beams, the lower portion of each loop or yoke engaging a detent, as12, secured to the lower faces of the beams of the frame 2. Each yokeextends thence upwardly, one leg thereof upon each side of itsrespective beam, the upper ends of the said yoke projecting throughapertures formed in the annular rim of the braceplate 10, where they aresecured in place by suitable nuts. The floor-frame may thus bethoroughly braced with respect to the center bearing of the device.-

The floor 1 is provided at its outer edge with an upwardly-extendingannular wall 13, and near its inner edge at a point a suitable distancefrom the post 7 the said floor is provided with an upwardly-extendinginner wall 14:. These walls form an annular compartment or receptacle,together with the floor, upon the floor-frame. The floor-frame 2 is alsoprovided with suitable means for rotating it upon its bearings. Vhile avariety of rotating means might be employed, I prefer to secure anannular rack, as 15, beneath the floor-frame at its outer edge, the saidrack being adapted to engage an actuating-pinion 16, secured to a shaft17 upon the foundation 5. This shaft 17 preferably carries a bevelgearwheel 18, meshing with a bevel-pinion19 upon a counter-shaft Thecounter-shaft 2O also carries fast and loose pulleys, as at 21 by whichit may receive motion through a suitable belt from any source of power.The relative sizes of the gears 18 and 19 will control the speedimparted to the table 1.

The standard 7 projects above the table 1 and its inclosing walls 13 andlt and is adapted to support a frame, as 20, which carries suitablemixing or stirring means. The frame 20 is formed of a series ofoutwardlyextending beams, as 21 21,which are held in position at thecenter of the machine by upper and lower hub-plates 22 and 23. Thesehubplates are splined to the standard 7, so that the frame may be raisedor lowered upon the said standard, but will not revolve about the same.The frame 20 is adjustably secured to the standard 7 by attaching theupper hubplate through the agency of links or chains 2 1 24 to the innerbifurcated ends 25 of an adj Listing-lever 26. This lever 26 isfulcrumed to a bracket 27, rigidly secured to the upper end of thestandard 7. The lever 26 is made sufficiently long to project beyond theedges of the table 1 and the foundation-frame 5, so that an operator orattendant may, by grasping the outer end of the said lever, raise orlower the frame 20 with respect to the floor 1. The timbers or beams ofthe frame 20 carry upon their under edges segmental frames, as 28, 29,and 30. These segmental frames are preferably struck from differentcenters, being arranged upon the arcs of different circles. Each frameis preferably formed of outer and inner curved pieces of angle-iron, as31 and 32, which are bolted to the beams 21 of the frame 20, and arefurther strengthened by being connected with each other by alattice-work of cross and diagonal bars 33 and 34. These segmentalframes therefore serve to brace the outer ends of the beams composingthe frame 20. The frame 29 is preferably arranged so that it connectsone end of the frame 28 with one end of the frame 30. The other ends ofthe frames 28 and are arranged at a suitable distance from each other,being separated or isolated. These segmental frames I employ to carrythe stirring means used above the floor 1. lVhile any suitable stirrersmay be employed for this purpose, I find that superior results areobtained by using plows, as 35 35. These plows are formed withupwardly-extending stems, as 36, which are secured to or formed integralwith approximately horizontally extending supporting-beams 37. The beams37 are preferably secured to the lattice-work of the segmental frames28, 29, and 30. The manner of their attachment is such that the saidbeams will be allowed a small amount of oscillation. One end of each ofthe said beams 37 is pivoted to a lug 39, which is secured to the underside of one of the lattice-bars 33. The said beams 37 are supported neartheir other ends within loops 38, formed upon suitable plates which arebolted to the latticebars. These loop-plates preferably have interposedbetween them and the lattice-bars cushion-blocks, as 40, preferablyformed of rubber or other elastic material. The beams 37 thus have aslight motion upon their fulcrums, the movement of the same beinglimited by the loops 39. This permits the plows to yield somewhat whennecessary, should they be caught in any manner upon the table.

The construction of the whole plow-frame is such that when it is loweredall the plows will be brought near the surface of the floor and inposition to stir or mix the materials carried around by the said floor.Although the plows on the frame may be arranged at any desired angles,they are preferably not turned much from coincidence with concentriclines on the floor. All the plows are arranged so that no one follows inthe same path traveled by another, so that the whole floor will bethoroughly covered by their operation. It is desirable, however, toarrange the plows upon one of the segments say segment 29so that it willturn their furrows in an opposite direction to the furrows turned by theplows upon the other segment. This arrangement further assists in thethorough mixing of the materials upon the table. \Vhen the framecarrying the plows is raised out of contact with the floor, it may beheld in said raised position by causing the lever 26 to engage a hook4:1 or any other suitable means secured to the frame 20 or elsewhere.hen the frame is to be lowered, it is merely necessary to disengage thelever 26 from said hook and allow the lever to move upwardly.

In order to facilitate the discharging of thoroughly-mixed materials onthe floor 1, I provide said floor with one or more trapdoors, as 42 12,only one of these doors being illustrated in the drawings, since it isdeemed suflicient to illustrate the construction so as to be readilyunderstood by those skilled in the art. I find that the use of threesuch doors is ordinarily suflicient to accomplish the desired purposes.These doors are preferably equidistant from each other and are hinged atone of their edges, as at 4:3, to the edge of the aperture in the floorwhich they are designed to close. These hinges are preferably of thepiano-hinge style, so that no crevices will be left for the material towork through. The doors 42 are held in their closed positions by meansof suitable latches or sliding bolts, preferably as at 44 44, the saidlatches moving in inclosing housings, being pressed outwardly by springslocated behind them. Each of the bolts 44 is provided with a shank orstem, which is connected with a chain, as 45, which chain is adapted tobe secured to a Windlass-rod, as 46, there being one windlassrod foreach trap-door. Each Windlass-rod is mounted in suitable bearingsbeneath the floor and extends nearly to the periphery of said floor,but, preferably, not across said rack 15, where it is provided with atrigger or operating-lever 47. A trip-block or obstacle,as 48, ispivoted to the foundation-frame 5, so as to be in the path of thetriggers 47 and in position to move the same to one side as the tablerevolves for rocking the Windlass shafts. hen a Windlass-shaft is thusrocked, the bolts 44 44 of the adjacent door will be retracted and thedoor will be permitted to fall by gravity, swinging downwardly upon itshinge. Each door is also provided with means for raising it again to itsclosed position, which means consists in a rock-shaft 49, secured to theunder side of the floor in suitable bearings arranged upon the oppositeside of the door from the latches. Each rock-shaft 49 carries one ormore levers or arms 50, which are arranged to press against the undersurface of its particular door. The rock-shafts 49 extend nearly to theperiphery of the floor 1, but preferably not across said rack 15, andare also provided with triggers 51 for rotating the said rock-shaft, thesaid triggers being similar to the triggers 47 of the Windlassshaft 46.These triggers 51 are arranged to be engaged by a trip-block 52,somewhat similar to the trip-block 48 and also secured to thefoundationframe 5 in the path of said triggers. In order that thetrip-block 48 may not engage the triggers 51 of the closing devices, thesaid trip-block 48 is arranged at a greater distance from the peripheryof the floor than the trip-block 52, which is designed to operate thesaid triggers 51. All the windlass-shafts are therefore extendedcorrespondingl y nearer to the periphery of the table than are therock-shafts 49.

Since it is not desired to open the doors except at the end of themixing operation, the trip-blocks 48 and 52 are so formed that they maybe quickly thrown out of operative position. Each of these trip-blocksis pivoted at one end to the frame 5. Each block is formed with atripping end, as 53, which projects upwardly from the plane of thepivoted end portion. By this shape it is possible to swing thetrip-blocks back and forth into and out of operative position. hen theblock is in the position shown in full lines in Fig. 5, its tripping endportion will engage the triggers of the door-operating mechanisms. Whenthe block is swung either inwardly or outwardly upon its pivot, thetripping end portion will not engage the triggers of the door-operatingmechanisms.

The foundation frame 5 is preferably formed with an open portion, as at54, to receive the discharged material from the floor 1, the said openportion of the frame also facilitating the removal of the said materialfrom the machine. The trip-blocks are arranged so that the latches 44will be released just as the door begins to pass over the open space 54,while the trip-block 52, which closes the doors, is arranged upon theother side of the said opening, thus giving ample opportunity for thematerial to pass through the open trap.

In the use of such a mixing apparatus it is also needful to have propermeans for the spreading of material upon the floor when newly dischargedthereon and, for scraping material from the said floor when thetrapdoors are opened. This I accomplish by arranging a scraper, as 55,above the floor 1 at a point to one side of the discharge-opening 54.This scraper 55 is suspended upon a rock-shaft 56, which extends acrossthe upper portion of the inclosure formed by the walls 13 and 14 and ispivoted at its inner end in a fixed collar 57, secured to the standard7, while the outer end of the said shaft finds a bearing in a post 58,arranged upon the baseframe 5. In order to operate the scraper, theouter end of the shaft 56 is provided with a crank-arm 59. Thiscrank-arm may have an operatinghandle, if desired, but is preferablyconnected by means of a link 60 with a vertical lever 61, fulcrumed uponthe base of the machine below the said rock-shaft. The use of the lever61 makes it possible to control the scraper with sufficient power tohold it firmly against the action of the material carried by the floor.It is only necessary to move the scraper about ninety degrees in orderto accomplish all the desired results. hen the scraper is raised to ahorizontal position, it will permit the material upon the floor to passbeneath it untouched; but when the said scraper is brought to a verticalposition it will be in a position to removeall the material from thesaid floor through the open doors. By holding the scraper atintermediate points itmay be made to even or smooth the surface of andproperly distribute the material upon the floor.

The operation of the machine in mixing concrete is somewhat as follows:Gravel'and cement are introduced upon the table-say from overheadtroughs or other similarmeansas the table revolves, the scraper beinglowered sufficiently, if desired, to operate as a spreader of thematerial. The handle of the forked lever 26 is then released and theplow-frame lowered until the mixingplows enter the materials forproducing the concrete, the said mixing-plows and frame beingnon-revoluble while said table revolves in a direction opposite to thedirection of the plow. During the mixing of the material water isapplied from a hose to the required amount. When sufliciently mixed, theplowframe is raised and the framelever secured by the hook 11, so thatthe said frame will remain in its raised position. The trip-blocks arethen set so as to engage the triggers first of the Windlass-shafts andthen of the rockshafts for closing the doors. As the traps aresuccessively opened over the space 54 the scraping-board is lowered, andall material is thus forced to pass through the open doors as the floorrevolves. After each door has discharged the material brought over itthe triggers of the closing-rod will engage their triplJlOCkS, and thedoors will be lifted, so as to be engaged by the locking-bolts again.After all the material has been scraped from the floor through the trapsand the traps have been closed the trip-blocks are thrown out ofposition until another batch of concrete has been mixed. A new supply ofmaterial can then be placed upon the table and the mixing op erationrepeated. in the meantime the concrete discharged into the opening 54:may be removed from beneath the machine.

From the above description it will be evident that a machine of thischaracter can be advantageously used for mixing concrete and likematerial, since the operation of the whole machine is entirely withinthe control of attendants, and the process can be carried on under theeye of an experienced person. By this means the concrete can be mixedneither too wet nor too dry, and the proper ingredients c: n be used inthe required quantities.

Having now described my invention, what 1 claim as new, and desire tosecure by Letters Patent, is g 1. in a concrete-mixer, the combinationof l a base, a revoluble floor mounted thereon, a non-revoluble framepositioned above said floor, depending stirring-plows provided withbeams pivotally secured to said frame at their forward ends, andlimiting-loops secured to said frame and loosely engaging said beamsintermediate of their ends, substantially as described.

9..In a concrete-mixer, the combination with a base of a revoluble floormounted thereon, a non-revoluble frame positioned above said floor,stirring-plows depending toward said floor from said frame and providedwith beams pivotally secured to said frame at their forward ends,limiting-loops secured to said floor and loosely engaging said beamsintermediate of their ends, and cushions interposed between said beamsand said frame, substantially as described.

3. In a concrete-mixer, the combination of a skeleton base, a revolublefloor mounted thereon, trap-doors positioned in said floor and hinged atone of their edges, springlatches for holding the doors in closedposition Windlass shafts connected with said latches by flexible meansadapted to be wound upon said shafts, triggers attached to saidWindlass-shafts, adjustable trip-blocks adapted to be brought into thepath of said triggers to operate said Windlass-shafts, and retract saidspring-latches, rock-shafts secured to said floor and provided with armsfor closing said doors, triggers secured to said rockshafts foroperating the same, adjustable tripblocks adapted to be brought into thepath of the last said triggers to operate the same, and means forrevolving said table, substantially as described.

In testimony whereof I hereunto afiix my signature in presence of twowitnesses.

HUGH MISCAMPBELL. lVitnesses:

ELLINGTON M. BLEWETT, JAMES T. WATsoN.

